The above-referenced parent application relates to X-ray apparatus which is used during a surgical procedure known as PTCA, or percutaneous transluminal coronary angioplasty. The apparatus therein described is specially adapted to facilitating the PTCA procedure by making it easier for the radiologist to integrate opacified (or "roadmap") information with real-time fluoroscopic information. The roadmap information shows information relating to the patient's circulatory system, while the fluoroscopic information shows information relating to the balloon catheter and its positioning with respect to the patient's skeletal system.
In PTCA, an inflatable catheter is introduced into the patient's circulatory system and guided to a stenosis (blockage) in the patient's heart. When the catheter is properly positioned, it is inflated to a greatly increased size and brought to bear against the stenosis. This causes the stenosis to be flattened against the arterial wall, clearing the artery and thereby improving blood flow through it.
Prior art X-ray equipment does not provide a convenient way for the radiologist to evaluate the success of the PTCA procedure. Conventionally, the radiologist does not objectively know, during the course of the PTCA procedure, whether the stenosis has been sufficiently flattened. The radiologist must judge the success of the operation subjectively. Thus, the radiologist may repeatedly inflate the balloon catheter when the stenosis has already been broken up, just to be sure that the catheter is not prematurely withdrawn from the patient's body. This additionally may prolong the procedure unnecessarily and is undesirable because the catheter remains in the heart when this is not strictly necessary.
One object of the invention is to provide a device which is usable by a radiologist during a PTCA procedure.
Another object of the invention is to provide a device which is usable by a radiologist in the sterile conditions of a catheterization laboratory while the radiologist is standing at the patient's bedside.
Still another object of the invention is to provide a device which allows a radiologist to compare arterial blood flow before and after the PTCA procedure so as to avoid, on the one hand, unnecessary inflation(s) of the balloon catheter, and on the other hand, premature withdrawal of the balloon catheter from the patient's body.
Yet another object of the invention is to provide a device which allows the radiologist to compare the dynamic motion of the heart both before and after the PTCA procedure so as to be better able to evaluate the improvement in heart performance after the procedure.